Engine-starter.



S. W. RUSHMORE. ENGlNE STARTER- APPLICATION FILED APR. I2, 1916.

Patented July 31, 1917.

Mi g! SAMUEL W. RUSHMORE, OF PLAINFIELD, NEW JERSEY.

ENGINE-STARTER.

Specification of Letters Patent.

Patented July 31, 1917.

Application filed April 12, 1916. Serial No. 90,536.

To all whom it may concern Be it known that I, SAMUEL IV. RUSH- MORE, a citizen of the United'States, and resident of Plainfield, in the county of Union and State of New Jersey, have invented certain new and useful Improvebe started.

A simple and effective way of securing the desired axial movement of the pinion into mesh when the power is applied, and out of mesh when the engine takes up its cycle of operation, is to mount it on the armature shaft of a small starting motor and so design the motor that a spring or other suitable means holds the armature in an axially displaced position with the pinion out of mesh when the motor is at rest; while upon closing the circuit of the motor, the armature is moved endwise/by the solenoid pull exerted by the field and the pinion is brought into mesh. As long as the motor continues to do work in driving the engine, the pinion and gear will stay in mesh, while, when the motor ceases to do work, either b the breaking of the circuitor by the driving of the motor from the engine after the starting of the latter under its own power, the pinion and armature automatically move axially in the opposite direction to disengage the starting motor and the engine.

In my prior and co-pending application, Serial No. 722,629, filed September 27th, 1912, I have illustrated a construction of this type in which the pinion is rigidly connected to the armature shaft. In the practical'employment of the specific form of.

starter described in said application, the pinion begins rotating during the initial endwise movement. This tends to interfere with the free sliding of the pinion into mesh, and if the pinion rotates at too high speed before it begins to mesh with the gear, the

. ends of the gear teeth will be battered together and injured, particularly if the ends of the gear teeth are not properly shaped.

One means which I have devised for pre- Venting this high speed rotation of the pinion before moving endwise into mesh, is described in my Patent No. 1,079,725, dated November 15, 1913. In the construction there shown, I retard the rotary movement of the armature pinion until the pinion and gear are in mesh, by shunting a part of the current around the armature until the engagement has been effected. Thus, at first, there is strong endwise pull on the pinion but very much less than maximum torque. This arrangement operates very satisfactorily and has gone into extensive use, but it involves the use of a somewhat complicated and expensive switching device and also of additional wires from the switch to the starting motor, all of which increase the cost of installation and increase the liability of short circuiting, of breaking, or disengaging of wire terminals.

The object of my present invention is to effectively secure the slight torque and slow rotation of the pinion during the endwise movement of it, by purely mechanical and positively acting mechanism and without increased complication or expense of the motor, wiring, or circuit controlling parts.

In the accompanying drawings, I have illustrated merely one embodiment of my invention and this embodiment is one particularly designed for use in connection with the general type of starter-shown in my prior application above referred to, but I do not desire to be limited to this specific construction or to the particular type of starter illustrated except as hereinafter defined in the claims.

In these drawings, to which reference is to be had and in which similar reference characters indicate corresponding parts in both views,

.Figure l is a somewhat diagrammatic illustration of one embodiment of my invention, the circuit being shown open and the parts in normal disengaged position; and

Fig. 2 is a View similar to Fig. 1 but showing the. parts in driving position and with the circuit closed.

In the Specific construction illustrated in the drawing, the internal combustion engine 10 has gear teeth 11 on the fly-wheel 12. Adjacentto the engine is mounted the starting motor including the usual armature 13 secured to an armature shaft 14 and disosed between the field poles 15, 15 The frame of themotor, which is shown in skeleton form but which in practice is usually a means. The collar and the pinion are northe poles.

engine.

The motor is shown as being an ordinary series wound motor and may be energized from any suitable source of electrical energy 21 and the circuit may be controlled by any suitable form of circuit closer 22. The

closing of the circuit causes a solenoid pull on the armature and an endwise'movement of the latter to a central position between the poles and in opposition to the spring 20. The parts so far described do not constitute any novel portion of my present invention andv are substantially the same as the corresponding parts shown in my 'prior application above referred to. They may be replaced by any other construction adapted for use in lconnection with the novel parts hereinafter described.

For connecting the motor to the engine, I

provide a pinion 23 which, upon proper axial movement, may mesh with the fly-.=

wheel gear 11 of the engine and as an important feature of my invention, I provide mechanical means which will permit the comparatively free relative rotation of the pinion on the shaft, the endwise sliding of the pinion along the shaft, and the positive clutching or interlocking of the pinion and shaft during the operation of starting the In the specific construction illustrated, the shaft is provided with a collar 25 rigidly secured against rotation or longitudinal movement by any suitable form of locking mally held in spaced relationship by a coil spring 27, one end of which seats against a retaining flange 24 and the other against the body of the pinion. The opposing faces of the pinion hub 26 and the collar 25 are provided with one-way driving clutch teeth normally out of engagement with each other.

-The shaft itself may carry a small collar,

flange or stop 28 limiting the movement of the pinion away from the collar 25 and thus limiting the extent to which the clutch members are normally spaced. apart. The motor frame is provided with a stop 29, which may be in the form of a flange, tolimit the movement of the pinion during the endwise movement of the shaft and the frame is also provided with a recess or is so designed that the collar 28 may move past the sto 29 and compel the clutch members to interibck shaft. I

From the foregoing, it will be seen that the collar 25 with its clutch teeth is rigid with the shaft while the pinion, when in the position shown in Fig. 1, is free to rotate. in respect to the shaft and the shaft may 0 be'moved endwise against the action of the spring 27 after the pinion strikes the stop 29, to bring the clutch members into engagement. When they are in engagement, the pinion will be caused to rotate with the The 0 eration of starting the en e ma be briefl y described as follows:

Upon closing the circuit of thegmotor, the field poles will be powerfully magnetized g0 and will exert 'a powerful .endwisepull on the armature to bring it into alinement' with the poles and against the influence of the spring 22.-" -While in the displaced position shown in Fig. 1, the field will not exertits 55 maximum rotative efiect upon the armature; due to the reduced area of the'efi'ec'tive magnetic field, and therefore less than themaximum rotative efiort will be exerted. As

the pinion 23 is free to rotate in respect my shaft first begins gotating, the pinion will be subjected to no rotative eflort except that due to the friction ofits bearing upon the shaft and of its contact wih' the collar 28' and the, spring 27. The friction tending to rotate the pinion will, however, be suficient to impart to it some rotative movement so that there will be little or no tendency for its teeth to meet end-on at high rotative speed, with the teeth of the fly-wheel gear., The pinion will move endwise with the armature shaft and with. slight rotative effect until it engages with the fly-wheel gear. If the teeth properly mesh, it may continue its. movement with the shaft until it reaches its final position and engages withthe stop 29 on the motor frame. If it does not properly mesh with the fly-wheel gear, the instant it engages with the latter, the armature shaft may continue mowing endwise in respect to the pinion while the pinion is rotated friction until it does come into mesh. While the pinion is moving end- 15 wise or after it has completed its endwise movement, the clutch member connected to the shaft will move endwise faster than, orfarther than, the inion and the clutch members will interloc Y The shaft can then no longer rotate in respect to the pinion and the entire rotative efi'ect exerted by the motor will be transmitted through the pinion to the fly-wheel gear and the engine will begin to turn over. Y

When the motor is driving the engine, a heavy current flows through the field coils 'and'the magnet is powerfully excited, and the endwise pull on the armature is sufficient to overcome the action of both of the springs 20 and 27. After the first explosion in the engine cylinder, the fiy-wheel and armature are rapidly accelerated and this develops a counter-electromotiv'e force in the armature which acts to reduce the effective current flow through the armature and field and'to reduce the axial magnetic pull on the armature to such an extent that it is no longer suflicient to overcome the combined force of the two springs 20 and 27. The combined effect of both springs will therefore act to shift the armature until the clutch members are thrown out of engagement and thereafter the pressure of the spring 20 alone will continue to shift the armature to the original displaced position. During this movement, the collar 28 will again come into engagement with the pinion and the latter will be forced out of engagement with the fly-wheel gear and the armature spin it at high speed in the disengaged position until the current supply to the motor is interrupted.

It will be readily understood'that my invention may be incorporated with the armature and fields forming the operating magnet as shown, or a separate magnet may be provided having its windings connected in series. In either event, the operating magnet will be influenced by the characteristic properties of a series field to effect disengagement of the pinion as the result of retention of current due to the increased counter-electromotive force of the speeding motor. If a separate magnet connected in series with the field be employed, the armature itself need not move endwise and the magnet may operate merely to move, endwise in respect to the motor, parts driven by the motor and corresponding to the parts between and includingthe collars 24c and 28 of the form shown. 7

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. The combination with an internal combustion engine and a starting motor, of a gear connected to said engine, a pinion slidable on the motor armature shaft and normally ofiset axially out of mesh with said gear, and means for moving said shaft and pinion axially to bring the latter into mesh and to lock said pinion against rotation in respect to said shaft.

2. The combination with an internal combustion engine and a starting motor, of a gear connected to said engine, a pinion on the motor armature shaft and normally offset axially out of mesh with the gear and normally freely rotatable and endwise slid-- able in respect to the armature shaft, clutch connections for locking said pinion and shaft against relative rotation, and means for moving said shaft and pinion axially to different distances to bring said pinion into member endwise and simultaneously rotating said member, and a stop for limiting endwise movement of the pinion after the latter is in mesh with said gear.

4:. In combination, an internal combustion engine, a gear connected thereto, a shaft, means for rotating said shaft at high speed and moving it endwise a limited distance,

a pinion normally free to rotate in respect to said shaft and offset axially out of mesh with said gear, normally disengaged clutch members carried by said shaft and said pinion, a spring for holding said clutch members in normally disengaged position, and a stop for limiting the endwise movement of said pinion with said shaft and permitting the further endwise movement of said shaft in respect to said pinion to bring said clutch members into engagement.

5. In combination, an internal combustion engine, a gear connected thereto, a shaft, a pinion normally free to rotate and slide endwise on said shaft, a pair of normally disengaged clutchf members for locking said pinion against rotation in respect to said shaft upon an endwise movement of said shaft in respect to said pinion, and a source of power operating to rotate said shaft and move it endwise to bring saidv pinion into mesh with said gear and said clutch members into engagement with each other.

6. A starter for internal combustion engines, including an electric motor having an endwise slidable armature, an armature shaft, a pair of spaced collars secured to said shaft, a pinion between said collars and rotatable in respect to said shaft, and slidable axially of said shaft into engagement with either collar, a spring normally tending to hold said pinion in engagement with one collar, clutch means for locking said pinion against rotation in respect to said shaft when in engagement with the other collar, and means for energizing said motor to move said armature endwise and rotate the same, and to bring said pinion into driving engagement with'the engine, and to effect the interengagement of said clutch members.

7. The combination with an internal combustion engine, of a gear member connected thereto, a driving shaft, a pair of spaced collars secured to said shaft, apinion disposed between said collars and slidable longitudinally of said shaft into engagement with either collar, said pinion being rotatable in respect to the shaft when in engagement with one'collar, a spring tending to hold said pinion in engagement with said last mentioned collar, means for preventing rotation of said pinion in respect to said shaft when in engagement with the other collar, means for rotating said shaft to drive the pinion by its frictional engagement with said spring, shaft and first mentioned colmemes lar, and moving said shaft endwise to brin said pinion into mesh with said gear, an

a stop for limiting the endwise movement of the pinion and permitting further end- 15 Wise movement of said shaft against the action of said spring and effecting the locking of the pinion to the shaft.

Signed at Plainfield in the county of Union and State of New Jersey this 10th 20 day of April A. D. 1916.

- SAMUEL W. RUSHMORE. 

